Silicon carbide semiconductor devices with a regrown contact layer
AssigneePowerSicel, Inc.
InventorsBart J. Van Zeghbroeck, John T. Torvik
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Abstract
Silicon carbide semiconductor devices having regrown layers and methods of fabricating the same in a self-aligned manner. According to one aspect of the invention, the method includes growing at least one layer of silicon carbide on a substrate, removing the device from a growth chamber to perform at least one processing step, and regrowing another layer of silicon carbide on the at least one layer. According to one embodiment of the invention, the regrown layer may be a heavily doped contact layer for the formation of low resistivity ohmic contacts.
Claims37
A method of forming a semiconductor device from Silicon Carbide (SiC), the method comprising the steps of:
- growing on a substrate at least a first layer of SiC material in a growth chamber;
- removing the device from the growth chamber to perform at least one process on the device;
- and
- regrowing a layer of SiC material on the device.
11 The method of claim 1, wherein the device is a p-n junction.
A method of forming a bipolar transistor in Silicon Carbide (SiC), the method comprising:
- growing a first layer of SiC material having a first conductivity type on a substrate, a second layer of SiC material having a second conductivity type on the first layer, and a third layer of SiC material having the first conductivity type on the second layer;
- exposing a portion of the second layer of SiC material;
- and
- regrowing a layer of SiC material on the exposed portion of the second layer of SiC material.
A method of forming a bipolar junction transistor from Silicon Carbide (SiC), the method comprising the steps of:
- forming a multi-layer structure including a base layer formed from SiC disposed between an emitter layer formed from SiC and a collector layer formed from SiC, wherein the base layer has one of a p-type conductivity and an n-type conductivity and the emitter and collector layers have one of the p-type and the n-type conductivity opposite the base layer conductivity;
- patterning at least one mesa structure in the emitter layer, wherein the mesa structure patterning step exposes a portion of the base layer;
- regrowing a contact layer of SiC on the exposed portion of the base layer;
- and
- forming at least one ohmic contact on the contact layer.
A semiconductor device fabricated from Silicon Carbide (SiC), the device comprising:
- a substrate;
- at least one layer grown from SiC material on the substrate;
- at least one other layer regrown from SiC material, wherein the at least one other layer includes a conductivity as regrown, free from any subsequent annealing, greater than the at least one layer;
- and
- at least one ohmic contact.
31 The device of claim 28, wherein the device is a p-n junction.
A bipolar junction transistor fabricated from Silicon Carbide, (SiC), the transistor comprising:
- a substrate;
- a collector layer formed from SiC material on the substrate and having a first conductivity type;
- a base layer formed from SiC material on the collector layer and having a second conductivity type;
- an emitter formed from SiC material on the base layer and having the first conductivity type;
- and
- a regrown base contact layer formed from SiC material regrown on the base layer
Dependencies are inferred from the claim text.